Objective We aimed to investigate the effects of different non-surgical embryo transfer devices,number of transferred embryos,embryo stage,and embryos obtained from different mouse strains on the efficiency of non-surgical embryo transfer in mice,and to compare the efficiencies of surgical and non-surgical embryo transfer,in order to establish a stable non-surgical embryo transfer technology system.Methods Mouse embryo transfer was carried out using non-surgical method.Results The pregnancy rates using two different non-surgical transfer devices were(75.00±0.00)％and(66.67±14.43)％,and the birth rates were(46.11±6.31)％and(18.89±0.96)％,respectively.Transfer of 10,15,and 20 embryos resulted in pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,and(66.67±23.09)％,and birth rates of(29.33±4.16)％,(38.67±4.81)％,and(17.00±3.46)％,respectively.When blastocysts and morulae were transferred non-surgically,the resulting pregnancy rates were(80.00±0.00)％and(46.67±11.55)％and the birth rates were(38.67±4.81)％and(10.22±2.77)％,respectively.Four strains(C57BL/6J,ICR,genetically modified mice A,genetically modified mice B)were used as donors for non-surgical embryo transfer,with resulting pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,(73.33±11.55)％,and(80.00±0.00)％,and birthrates of(26.67±2.67)％,(38.67±4.81)％,(32.00±3.53)％,and(29.34±2.31)％,respectively.Fifteen pseudo-pregnant mice were transplanted surgically and 15 were transplanted non-surgically,with pregnancy rates of(80.00±0.00)％and(86.67±11.55)％,and birth rates of(38.67±4.81)％and(36.00±5.82)％,respectively.Conclusions Transfer device A resulted in a higher birth rate in this study.The embryo transfer efficiency was higher when 15 embryos were transferred into unilateral uterine horns of pseudo-pregnant 2.5-day recipients.Blastocyst-stage embryo transfer was more efficient than morula-stage transfer.There was no significant difference in efficiency between surgical and non-surgical embryo transfer procedures.

Objective We aimed to investigate the effects of different non-surgical embryo transfer devices,number of transferred embryos,embryo stage,and embryos obtained from different mouse strains on the efficiency of non-surgical embryo transfer in mice,and to compare the efficiencies of surgical and non-surgical embryo transfer,in order to establish a stable non-surgical embryo transfer technology system.Methods Mouse embryo transfer was carried out using non-surgical method.Results The pregnancy rates using two different non-surgical transfer devices were(75.00±0.00)％and(66.67±14.43)％,and the birth rates were(46.11±6.31)％and(18.89±0.96)％,respectively.Transfer of 10,15,and 20 embryos resulted in pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,and(66.67±23.09)％,and birth rates of(29.33±4.16)％,(38.67±4.81)％,and(17.00±3.46)％,respectively.When blastocysts and morulae were transferred non-surgically,the resulting pregnancy rates were(80.00±0.00)％and(46.67±11.55)％and the birth rates were(38.67±4.81)％and(10.22±2.77)％,respectively.Four strains(C57BL/6J,ICR,genetically modified mice A,genetically modified mice B)were used as donors for non-surgical embryo transfer,with resulting pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,(73.33±11.55)％,and(80.00±0.00)％,and birthrates of(26.67±2.67)％,(38.67±4.81)％,(32.00±3.53)％,and(29.34±2.31)％,respectively.Fifteen pseudo-pregnant mice were transplanted surgically and 15 were transplanted non-surgically,with pregnancy rates of(80.00±0.00)％and(86.67±11.55)％,and birth rates of(38.67±4.81)％and(36.00±5.82)％,respectively.Conclusions Transfer device A resulted in a higher birth rate in this study.The embryo transfer efficiency was higher when 15 embryos were transferred into unilateral uterine horns of pseudo-pregnant 2.5-day recipients.Blastocyst-stage embryo transfer was more efficient than morula-stage transfer.There was no significant difference in efficiency between surgical and non-surgical embryo transfer procedures.